90 THE NAUTILUS. 



dead shells on July 9 at Clay, Clay Co. The type-set is from Gas- 

 saway, Cam. Mus., no. 615399. 



This form may be described as a rather small and somewhat flat- 

 tened subrotunda. It corresponds to a degree to the var. Mrtlandi- 

 ana (Lea) of the upper Tuscaravvas, Beaver and French Creek 

 drainages in Ohio and Pennsylvania, but it is not quite so flat as the 

 latter, is smaller, and has not the subulate shape of the upper poste- 

 rior part. In fact, in shape it does not differ much from typical sub- 

 rotunda, and moreover, the degree of compression is quite variable. 



The soft parts, however, show some very marked peculiarities in 

 their color. While typical subrotunda has either orange or whitish 

 soft parts, with the placentas and eggs (and of course the gills of the 

 gravid female) always of a red color, in the Elk River form the soft 

 parts are of the white type, and placentae and eggs are white. This, 

 at least, is the rule. But there are rare exceptions : at Gassaway I 

 found a single male, which had orange soft parts, and at Shelton I 

 found a few males and females with orange soft parts, and a few 

 females had cream-colored, pink or red placenta? ; in one case only 

 orange soft parts and red placenta? were associated. This shows 

 clearly that the Elk River shell is to be regarded only as a local race 

 of subrotunda, probably passing into the normal form in the lower 

 part of Elk River (Shelton, where the greatest number of specimens 

 with red or orange was found, is the lowermost point where I col- 

 lected. 



The anatomy of this form is absolutely identical with that of sub- 

 rotunda. On all three dates I found gravid females, but on May 25 

 they all had only eggs ; on the other days glochidia were present. 

 One specimen collected July 8 had the ovisacs only partly charged, 

 and in a number of them the basal part was empty, while the distal 

 part contained yet parts of the placenta?. This shows that the pla- 

 centa? are sometimes discharged in sections. Glochidia identical in 

 shape and size with those of subrotunda and kirtlandiana (Ortmann, 

 Mem. Cam. Mus., 4, 1911, pi. 89, fig. 1). Length, 0.13; height, 

 0.15 mm. 



FUSCONAJA BURSA-PASTORIS (B. H. Wright). (See Quadrula b.-p. 

 Simpson, 1900, p. 791). 



I collected a number in Clinch River, at Richland and Raven 

 Tazewell Co., Va., on Sept. 20 and 21, 1912. 



